// flow原始类型
/**
 * @flow
 */

// js原始数据类型目前六个：String/Number/Bolean/Undefined/Null/Symbol
// 后期：BigInt

const str: string = 'fss'
const num: number = 100 || NaN || Infinity //Infinity:无穷大 
const bol: boolean = true || false
const nul: null = null
const vo: void = undefined
const sy: symbol = Symbol()